1. Field of the Invention
The present invention related to a semiconductor package device, and more particularly to dispose the heat dissipation structure with a higher heat conductive coefficient on the die to increase the heat dissipation efficiency for the semiconductor package device.
2. Description of the Prior Art
Please refer to FIG. 1, which shows a cross-sectional view of the conventional ball grid array (BGA) package device. BGA package device 100 includes a semiconductor die 120 which is disposed on carrier substrate 110 (or substrate 110), and is electrically connected carrier substrate 110 via the plurality of conductive wire 130. A plurality of connecting components 150 is disposed on the back surface (not shown) of carrier substrate 110 corresponding to the top surface (not shown) of carrier substrate 110. The coefficient of thermal expansion of the die 120 is about 2.5×10−6/K˜3.5×10−6/K. According to the heat dissipation during the operation of the semiconductor package device, heat dissipation structure 160 is disposed on package body 140 and the top surface of carrier substrate 110 to increase the heat dissipation efficiency of semiconductor package device as shown in FIG. 2.
PBGA (Plastic ball grid array) is one of the IC package techniques available for a die, the mainly dissipation mechanism comes from the printed circuit board with larger dissipation area. When the heat is transferred to the printed circuit board through the holes (now shown) of the carrier substrate or through the solder ball, the printed circuit board has enough space and the air to perform a heat exchange process via the heat conversion and heat radiation to dissipate the heat. According to the proportion of the heat dissipation, the 85%˜95% of heat is dissipated from this dissipation path which is generated from the die. Thus, the heat dissipating performance of PBGA is depended on the design of the printed circuit board. When the requirement of the package system tends to small-scale, the heat dissipation would be an issue for the printed circuit board is to be shrunk. Thus, a heat dissipation mechanism is added on the top of the package body which is a commonly method. By increasing the heat dissipation path on the top of the package body, the dissipation proportion of the heat source of die is increased from 5%˜10% to 15%˜25%. Unfortunately, the heat dissipating performance would be limited due to the dissipation of the heat source is fixed under a proportion. Therefore, the dissipation limitation of the package device cannot break the dissipation requirement is about 10 Watts. The dissipation limitation of the package device is the thickness of the package device, according to the wire bond design rule to regulate the distance between the top of the conductive wire and the package body and the distance of the top of the conductive wire is electrically connected the carrier substrate that is not to be small than 4 miles. Thus, the thickness of the top of the die must be larger than the 8 miles. The coefficient of thermal expansion for filing materials is about 0.1 W/m-K˜1.0 W/m-K, which is disposed between the top of the conductive and the package body. Thus, the heat conduction is to be limited, the design and the application for the improved BGA package device with heat dissipation structure cannot provide the heat conduction in longitude direction in this gap between the package body and the conductive wire, and the design and the application for the improved BGA package device with heat dissipation structure merely increases the heat dissipation in plane surface of the package device. Thus, the important issue is to solve the lower heat conduction in longitude direction to increase the heat dissipating performance of the PBGA with the exterior heat dissipation structure.